1. Field of the Invention
The present invention relates to devices for climbing structural members and more particularly pertains to an improved portable device for safely and quickly attaching to upright wooden studs.
2. Description of the Prior Art
It is often necessary to attain heights along various structures that are beyond a person's normal reach. While ladders or scaffolding may be erectable near a particular structure to provide the necessary height, such devices are usually bulky and heavy, and consequently, cumbersome to transport, erect, and relocate. Space limitations or the lack of proper footing may preclude the use of a ladder or scaffolding altogether. The prior art has provided a number of compact devices that rely on an existing structure for support. These devices are usually configured to grasp a conveniently positioned structural member in some manner, and are typically frictionally held or locked in place upon application of weight onto their supporting surface.
U.S. Pat. No. 3,561,563 to Harsh and U.S. Pat. No. 4,754,841 to Koffski are representative examples of the prior art. Each describes a rather simple device whose position along a vertically disposed post is easily adjustable by simply lifting on its outward extension to disengage the gripping surfaces from the post and then simply sliding the entire device up or down. The device is subsequently held or locked in place by applying weight to the outwardly extending support member. The offset cantilevered arrangement of the support member in relation to the gripping surfaces provides the necessary leverage to firmly grip the post at that position.
Disadvantages inherent in the prior art are as follows. Devices similar to that described by Harsh, while providing an extremely simple, easily transportable and quickly attachable post step, pose a safety hazard as the step can easily be laterally displaced before a sufficient amount of weight has been applied thereto to lock it in place and consequently can cause the user to lose his or her footing. In addition, when such a device is attached about a stud having an uneven surface, a correspondingly unevenly distributed grip may allow the entire device to twist during use, again presenting the potential for injury.
While Koffski overcomes the described safety-related problems associated with Harsh, a Koffski-type of design entirely surrounds the post or stud member to which it is attached and therefore requires that the device is introduced over the end of such a member. This automatically precludes its use on structural members that have cross members attached thereto or where the end of the member is out of reach such as typically encountered at a construction site.
An improved device is called for that overcomes these described shortcomings and disadvantages inherent in the prior art.